Screw-driver



(Model.)

0. THOMAS.

SGREW DRIVER.

'No. 258,329. Patented May 23, 1 882.

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UNITED STATES PATENT OFFICE.

GAL THOMAS, OF TERRE HAUTE, INDIANA.

SCREW-DRIVER.

SPECIFICATION forming part of Letters Patent No. 258,329, dated May 23,1882. Application filed February 16, 1882. (ModeL) To all whom it mayconcern:

Be it known that I, CAL THOMAS, a citizen of the UnitedSt-ates, andresident of the city of Terre Haute, Vigo county, Indiana, have inventeda new and useful Screw- Driver and Screw-Adjuster, of which thefollowing is a specification.

My invention relates to improvements in screw-drivers in whichclamping-jaws are used for holding the screw in contact with the driverwhen entering it into the material into which it is to be driven; andthe objects of my improvements are to provide certain novel devices andcombinations thereof,which,when properly arranged, shallconstitute ascrew-driver,which, when a screw is properly placed in it,wi1l hold itin position for being entered intothe substance into which it is to bedriven, and at the same time cause the dogs which hold the screw, asabove described, to automatically recede sufficiently far to allow thescrew to be driven to sucha depth as to allow the outer surface of itshead to be flush with the surface of the substance. I attain theseobjects by the devices and combinations illustrated in the accompanyingdrawings, in which-- Figure 1 is a plan View ofan ordinary screwdriverwithout having applied to it any means of holding the screw in contacttherewith. Fig. 2 is a plan view of my improved device, showing theclamping-jaws, the tool which enters the slot formed in thehead of thescrew, a screw in dotted lines, and the position of the jaws whileclamping the screw. Fig. 3 is a sectional elevation, showing a portionof the recessed handle, the hollow shank, the enlargement upon its outerend, the rod, and mechanism for operating the dogs, and the jaws forclamping the screws; and Fig. 4 is an end view, showing the enlargementon the end of the shank, the tool which enters the slot in the head ofthe screw, and the clampingjaws.

Similar letters refer'to similar parts throughout the several views.

In constructing this type of screw-driver I provide a handle, A, of anysuitable material and form, which, when made of wood,is provided uponits inner end with a metal ferrule, B, as shown in the drawings. In theinner end of the handle there is formed an annular recess, in whichthere is placed a spiral spring,

A, which is designed to operate the clampingjaws, as will hereinafter bedescribed. The

sides of the handle A may be flattened, if preferred, but in any eventthere is to be hinged to it an arm, A the inner end of which enters thehandle far enough to allow it to come in contact with an enlargementformed on the rod which operates the clamping-jaws, as shown in Fig. 3.

In making provision for holding the screw in proper position for beingentered into the substance that is to'receiv e it, I provide a hollowstock or rod, 0, to the outer end of which thereis secured a ferrule,the outer end of which is constructed as shown, and is furnished with aslot or groove, into which there is placed a tool, F, which, when thescrewis being turned, enters the slot in its head and causes it to turnas the tool is turned. The enlarged portion F, being hollow, affordsroom within it for the arrangement of two clamping-jaws, F and F whichwork in slots formed in the outer end of the enlargement F, their innerends being pivoted to short connecting-links F F or said links may bedispensed with and the inner ends of the jaws be connected to the end ofa sliding rod, 0, which passes through the shank O and enters the handleA, passes through the spiral spring A, and terminates in an enlargement,G which has in it a notch or recess, which forms a shoulder againstwhich the arm A presses when its outer end is by the pressure of thehand of the operator brought into the position shown in dotted lines inFigs. 2 and 3, at which times the clamping-jaws F and F will be in theposition shown in dotted lines in Fig. 3, at which times they will notact upon the screw at all, but upon removing the pressure of the handfrom the arm A 'thesprin g will cause the rod 0 and the jaws F F to bemoved so as to cause the latter to clamp the head of the screw, as shownin Fig. 2, and thus hold it in position to be driven home.

As the arm A will at times protrude some distance from the handle, andthus be the source of annoyance,Iprefer in some cases to operate the rod0 and the clamping-jaws by a crosshead, or a rod placed in a slot formedin the handle A, its ends projecting just far enough to allow theoperator to place a thumb and finger thereon for the purpose of movingtheparts.

This proposed-method of operating the parts does not in any sense affectthe principle ofopinterior of which the clamping-jaws are pivoted,

a sliding rod, 0, which passes through the r 5 shank and enters thehandle A, clamping-jaws F F, a spring, A, for operating said jaws,located in the handle, and a lever, A or equivalent device, foroperating the clamping-jaws, the parts being constructed and arrangedsub- 20 stant-ially as and for the purpose set forth.

GAL THOMAS.

Witnesses WILLIAM MAeK, J. R. THOMAS.

